Pseudosclerodermatous triad of perniosis, pulp atrophy and 'parrot-beaked' clawing of the nails--a newly recognized syndrome of chronic crack cocaine use.

The number of people dependent on crack-cocaine in the UK has increased substantially in recent years. Some crack-cocaine users develop coarsening changes in the appearance of their hands after prolonged use of the drug. These changes have most often been recognized in females and include: (i) Perniosis with cold, numb hands, sometimes with perniotic hyperkeratosis over the knuckles.(ii) Finger pulp atrophy of the distal part of the pulps of some digits, especially the thumbs and index fingers.(iii) Claw-like curvature of the nails. As the distal pulp is lost, it can no longer splint the nail straight and so the nail curves, claw-like, and reminiscent of a parrot's beak as it clings to the new contour. As the pulp atrophy progresses, the nail eventually also becomes smaller.This triad may be due to ischemia consequent upon peripheral vasoconstriction induced by crack-cocaine. Early changes may resolve with abstinence. In the patients described the syndrome does not appear to be to related to intravenous drug usage. It may occur without concomitant use of heroin, whether smoked or via the intravenous route. The syndrome does not occur in all crack-cocaine users. It is hypothesized that those with a vasoreactive circulation (i.e., those with vasomotor instability/perniosis) are more susceptible to this reaction pattern. The syndrome consisting of the triad of perniosis, pulp atrophy and parrot-beaked clawing of the nails should alert the clinician to the possibility of prolonged crack-cocaine misuse.

Deoxycholate induces mitochondrial oxidative stress and activates NF-kappaB through multiple mechanisms in HCT-116 colon epithelial cells.

Nuclear factor kappa B (NF-kappaB) is a redox-associated transcription factor that is involved in the activation of survival pathways. We have previously shown that deoxycholate (DOC) activates NF-kappaB in hepatocytes and colon epithelial cells and that persistent exposure of HCT-116 cells to increasing concentrations of DOC results in the constitutive activation of NF-kappaB, which is associated with the development of apoptosis resistance. The mechanisms by which DOC activates NF-kappaB in colon epithelial cells, and whether natural antioxidants can reduce DOC-induced NF-kappaB activation, however, are not known. Also, it is not known if DOC can generate reactive oxygen species within mitochondria as a possible pathway of stress-related NF-kappaB activation. Since we have previously shown that DOC activates the NF-kappaB stress-response pathway in HCT-116 cells, we used this cell line to further explore the mechanisms of NF-kappaB activation. We found that DOC induces mitochondrial oxidative stress and activates NF-kappaB in HCT-116 cells through multiple mechanisms involving NAD(P)H oxidase, Na+/K+-ATPase, cytochrome P450, Ca++ and the terminal mitochondrial respiratory complex IV. DOC-induced NF-kappaB activation was significantly (P < 0.05) inhibited by pre-treatment of cells with CAPE, EGCG, TMS, DPI, NaN3, EGTA, Ouabain and RuR. The NF-kappaB-activating pathways, induced by the dietary-related endogenous detergent DOC, provide mechanisms for promotion of colon cancer and identify possible new targets for chemoprevention.

Esophageal acid exposure at pH < or = 2 is more common in Barrett's esophagus patients and is associated with oxidative stress.

Barrett's esophagus (BE) patients demonstrate a higher distal esophageal acid exposure profile than other gastroesophageal reflux disease patients. Cellular oxidative stress has been proposed to contribute to the development of BE and esophageal adenocarcinoma. However, a relationship between low esophageal pH and oxidative stress has yet to be elucidated. The aim of this study was to determine the duration of low pH exposure in the esophagus of BE patients compared to those with erosive esophagitis (EE) and to test if brief exposure to low pH leads to the induction of reactive oxygen species (ROS). Seventy-three patients with BE or EE were evaluated by 24-hour esophageal pH monitoring and the percentage of time during which there was exposure to pH < or = 4 and pH < or = 2 was recorded. In vitro, Seg-1 and Het-1A cells were evaluated after brief exposure to pH4 or pH2 by flow cytometry and fluorescent microscopy for the production of ROS. BE patients demonstrated a significantly higher exposure to low pH values (pH < or = 2) than EE patients. The mean percent total time, duration and mean number of reflux episodes at pH < or = 2 were 2.8 +/- 0.53%, 28.8 +/- 3.6 seconds and 79 +/- 11.4 episodes in BE patients, whereas in EE patients they were significantly less, 1.16 +/- 0.3%, 15.6 +/- 1.2 seconds and 48.3 +/- 8.8 episodes, respectively (P < 0.05). In vitro experiments indicate that esophageal cells, when exposed to pH 2, produce ROS. In vitro studies using brief pH 2 exposure are biologically relevant to the clinical situation. Our studies indicate that such exposure induces oxidative stress. This stress may cause DNA damage, mutations and progression to cancer.

Mitochondrial perturbation attenuates bile acid-induced cytotoxicity.

Hydrophobic bile acids such as deoxycholate (DOC) are known to damage liver cells during cholestasis and promote colon cancer. Cellular stresses induced by bile acids, which include mitochondrial and endoplasmic reticulum (ER) stresses, can result in apoptosis. We found that inhibition of mitochondrial complexes I-V with rotenone, thenoyltrifluoroacetone (TTFA), antimycin A, myxothiazol or oligomycin strongly protected against DOC-induced apoptosis of HCT-116 cells. To understand the mechanism of this protection, we explored the ability of these specific inhibitors to reduce DOC-induced mitochondrial and ER stresses. Different inhibitors markedly reduced DOC-induction of mitochondrial condensation, the DOC-induced decrease in mitochondrial membrane potential and the DOC-induced dilatation of the ER (evidence of ER stress). A dramatic induction of nucleolar segregation by antimycin A and myxothiazol, two distinct complex III inhibitors, was also observed. These findings strongly implicate mitochondrial crosstalk with apoptotic signaling pathways and mitochondrial-nucleolar crosstalk in the development of apoptosis resistance in the colon.

The hyfrecator: a treatment for radiation induced telangiectasia in breast cancer patients.

Radiation induced telangiectasia is a common problem in breast cancer survivors. By interfering with choice of clothing and acting as an unpleasant visible reminder of their disease, it negatively affects quality of life. The hyfrecator, based on the principles of electrosurgery, is a standard treatment modality for facial telangiectasia. This study aims to demonstrate the efficacy and tolerability of the hyfrecator as a treatment for radiation induced telangiectasia. Patients with radiation induced telangiectasia of breast or chest wall were prospectively identified from the breast cancer follow up clinic and offered treatment with the hyfrecator (sessions at 8 weekly intervals). Pre- and post-treatment photographs were obtained in a standardized manner and two blinded physician observers evaluated response. A linear analogue scale (LAS) was used by the patients to evaluate treatment response and any discomfort. At the end of treatment, patients completed a quality of life questionnaire. Of 16 patients enrolled, 15 completed the study. Treatment benefited all patients with severe or marked telangiectasia. Complete disappearance of telangiectasia was achieved in the majority (88%) of patients by the end of treatment. A median of six sessions (range 3-9) was required. All but one (93%) considered the treatment worthwhile. The majority (69%) judged the treatment to be painless or only mildly painful. 73% reported an improvement in self-confidence. The treatment was well tolerated by all the patients. All patients showed a remarkable clearance of vessels with a high degree of satisfaction with the results. Treatment with the hyfrecator is very effective for radiation induced telangiectasia. Three to four sessions achieve a substantial objective and subjective reduction in telangiectasia with a concomitant improvement in quality of life. It is a cost effective, ambulant out patient procedure requiring no local anaesthesia.

Bile acids as carcinogens in human gastrointestinal cancers.

Bile acids were first proposed to be carcinogens in 1939 and 1940. On the basis of later work with rodent models, bile acids came to be regarded as cancer promoters rather than carcinogens. However, considerable indirect evidence, obtained more recently, supports the view that bile acids are carcinogens in humans. At least 15 reports, from 1980 through 2003, indicate that bile acids cause DNA damage. The mechanism is probably indirect, involving induction of oxidative stress and production of reactive oxygen species that then damage DNA. Repeated DNA damage likely increases the mutation rate, including the mutation rate of tumor suppressor genes and oncogenes. Additional reports, from 1994 through 2002, indicate that bile acids, at the increased concentrations accompanying a high fat diet, induce frequent apoptosis. Those cells within the exposed population with reduced apoptosis capability tend to survive and selectively proliferate. That bile acids cause DNA damage and may select for apoptosis-resistant cells (both leading to increased mutation), indicates that bile acids are likely carcinogens. In humans, an increased incidence of cancer of the laryngopharyngeal tract, esophagus, stomach, pancreas, the small intestine (near the Ampulla of Vater) and the colon are associated with high levels of bile acids. The much larger number of cell generations in the colonic (and, likely, other gastrointestinal) epithelia of humans compared to rodents may allow time for induction and selection of mutations leading to cancer in humans, although not in rodents.

The obesity syndrome and acanthosis nigricans. Acanthosis nigricans is a common cosmetic problem providing epidemiological clues to the obesity syndrome, the insulin-resistance syndrome, the thrifty metabolism, dyslipidaemia, hypertension and diabetes mellitus type II.

Obesity and its consequences are arguably the chief public health problems facing the developed world. Obesity causes many fatal diseases, in particular cerebrovascular and cardiovascular disease. Acanthosis nigricans (AN) is a common cosmetic disability in pigmented ethnic groups. It may present with periorbital darkening or darkening of the neck or knuckles as well as acrochordons (skin tags) around eyelids, neck or axillae. The more classical AN of axillae and groins is less often a cosmetic disability, although it is an important physical sign. AN is very common in pigmented populations throughout the world, irrespective of domicile. It is rare in whites. AN is closely associated with all the features of the insulin-resistance syndrome (IRS), especially obesity. AN and IRS share a similar prevalence and epidemiology. IRS (also known as syndrome X or the deadly quartet) is characterized by insulin resistance (IR) and its associated conditions, including obesity, dyslipidaemia, hypertension and diabetes mellitus (DM) type II. The sequelae of IRS are cardiovascular and cerebrovascular disease. The origins of insulin resistance and its sequel, IRS, are debated. Insulin resistance can result from obesity. Also obesity usually presents before AN, hypertension or DM II. For these reasons it may be more helpful to recognize instead an obesity syndrome. The obesity syndrome is characterized by a genetically determined thrifty metabolism that protects subjects in famine conditions but which, in conditions of plenty, leads to weight gain with all its consequences, including hyperlipidaemia, hypertension, IR with DM II, and, in due course, cerebrovascular and cardiovascular disease. In pigmented races, AN is an important early manifestation of the obesity syndrome. AN helps identify persons at particular risk of developing the obesity syndrome, dyslipidaemia, hypertension and IR with DM II. Recognition of AN, therefore, offers important opportunities for health screening and preventative medicine.

Caspase-6 mediated cleavage of guanylate cyclase alpha 1 during deoxycholate-induced apoptosis: protective role of the nitric oxide signaling module.

Hydrophobic bile acids such as deoxycholate are known tumor promoters in the gastrointestinal tract. We have previously shown that deoxycholate induces apoptosis in colon epithelial cells and that these cells can be made resistant to deoxycholate-induced apoptosis. We now show that the nitric oxide synthase/nitric oxide/guanylate cyclase/cyclic guanosine monophosphate/cGMP-activated protein kinase (NOS/NO/GC/cGMP/PKG) signaling module contributes, in part, to the observed resistance of the cultured DOC-resistant colon epithelial cells (HCT-116R) using pharmacological inhibitors/antagonists (NS2028, Rp-8pCPT-cGMP, KT5823) of members of this signaling module. A novel finding from this study is the caspase-6 mediated cleavage of guanylate cyclase alpha 1 during deoxycholate-induced apoptosis of deoxycholate-sensitive HCT-116SA cells and the absence of guanylate cyclase alpha 1 cleavage in deoxycholate-treated HCT-116R resistant cells using Western blot analyses. This cleavage was specific to caspases as lysosomal, proteasomal, serine protease, cathepsin and calpain inhibitors failed to prevent the cleavage, whereas a general caspase inhibitor and a specific caspase-6 inhibitor did prevent guanylate cyclase alpha 1 cleavage.

Activation of the metallothionein IIA promoter and other key stress response elements by ursodeoxycholate in HepG2 cells: relevance to the cytoprotective function of ursodeoxycholate.

Ursodeoxycholate, used to treat a variety of pathologies, has the ability to reverse cytotoxic and hepatotoxic conditions. We examined HepG2, a hepatic cell line, treated with increasing levels of ursodeoxycholate, for responses of a range of promoters/response elements responsive to DNA damage, heavy metal ions, protein denaturants, aromatic hydrocarbons, retinoids, changes in intracellular AMP levels, end endoplasmic reticulum stress. The metallothionein IIA promoter was the most highly activated by ursodeoxycholate. Since ursodeoxycholate protects against the cytotoxic effects of deoxycholate, our data, combined with observations made by others, implicate metallothionein IIA as being important in this protective pathway.

Role of tachykinins in the host response to murine gammaherpesvirus infection.

Tachykinins function not only as neurotransmitters but also as immunological mediators. We used infection of tachykinin-deficient (PPT-A(-/-)) mice and wild-type controls with murine gammaherpesvirus to assess the role of tachykinins in the host response to a virus infection. Although infection was ultimately controlled in PPT-A(-/-) mice, there were higher titers of infectious virus in the lungs, accompanied by a more rapid influx of inflammatory cells. Clearance of latently infected cells from the spleen was also delayed. This is the first report of the direct influence of tachykinins in the host response to a virus infection.

Elastosis perforans serpiginosa and associated disorders.

We report elastosis perforans serpiginosa (EPS) arising in three patients with Ehlers-Danlos syndrome, osteogenesis imperfecta and Down's syndrome. These cases illustrate some of the rare but well-recognized disease associations with EPS. The other causes of EPS are reviewed.

Skin diseases in Ghana and the UK.

BACKGROUND: Although diseases of the skin have been studied in some African countries, the provision of dermatology services is as yet a relatively underdeveloped aspect of medicine in sub-Saharan Africa. OBJECTIVE: To determine the pattern of skin diseases seen in a sub-Saharan community and to compare it with that seen in a European community. METHODS: The diagnoses of the principal presenting complaint of 2254 consecutive new patients seen at the dermatology clinic of Komfo Anokye Teaching Hospital (KATH), Kumasi, Ghana, are presented and compared with those of 3383 consecutive new patients seen at the dermatology clinic of The William Harvey Hospital (WHH), Ashford, Kent, UK. RESULTS: The most common conditions in Ghana were infections (46.3%; UK, 12%). In the UK, the most common conditions were malignant and premalignant diseases of the skin (22.2%; Ghana, 0.5%) and benign tumors (16.8%; Ghana, 0.5%). Dermatitis was common in both countries (Ghana, 18.4%; UK, 16.0%). Psoriasis was more common in the UK (6.2%) than in Ghana (0.4%). In Ghana, fixed drug eruption, mainly due to cotrimoxazole (Septrin), was not rare (27 cases), and complications from cosmetic skin lightening creams were a frequent problem among women (86 cases). No cases of rosacea were found in Ghana, but it was not uncommon in the UK (1.6%). CONCLUSIONS: The patterns of skin diseases are different in the two countries. It is hoped that this study may help to catalyze the further development of dermatology services in Ghana.

Induction of mitochondrial changes in myeloma cells by imexon.

Imexon is a cyanoaziridine derivative that has antitumor activity in multiple myeloma. Previous studies have shown that imexon induces oxidative stress and apoptosis in the RPMI 8226 myeloma cell line. This study reports that imexon has cytotoxic activity in other malignant cell lines including NCI-H929 myeloma cells and NB-4 acute promyelocytic leukemia cells, whereas normal lymphocytes and U266 myeloma cells are substantially less sensitive. Flow cytometric experiments have shown that imexon treatment is associated with the formation of reactive oxygen species (ROS) and the loss of mitochondrial membrane potential (Deltapsi(m)) in imexon-sensitive myeloma cell lines and NB-4 cells. In contrast, reduction of Deltapsi(m) and increased levels of ROS were not observed in imexon-resistant U266 cells. Treatment of imexon-sensitive RPMI 8226 cells with the antioxidant N-acetyl-L-cysteine (NAC) protects cells against these effects of imexon. Mitochondrial swelling was observed by electron microscopy in RPMI 8226 myeloma cells treated with 180 microM imexon as early as 4 hours. Damage to mitochondrial DNA was detected by a semiquantitative polymerase chain reaction assay in imexon-treated RPMI 8226 cells; however, nuclear DNA was not affected. Finally, partial protection of RPMI 8226 cells against the imexon effects was achieved by treatment with theonyltrifluoroacetone, an inhibitor of superoxide production at mitochondrial complex II. These changes are consistent with mitochondrial oxidation and apoptotic signaling as mediators of the growth inhibitory effects of imexon. Interestingly, oxidative damage and decrease of Deltapsi(m) induced by imexon highly correlates with sensitivity to imexon in several myeloma cell lines and an acute promyelocytic leukemia cell line. (Blood. 2001;97:3544-3551)

Catalase-overexpressing thymocytes are resistant to glucocorticoid-induced apoptosis and exhibit increased net tumor growth.

Glucocorticoids are used for the treatment of lymphoid neoplasms, taking advantage of the well-known ability of these compounds to cause apoptosis in lymphoid tissues. Previously, we have shown that dexamethasone, a synthetic glucocorticoid, causes a down-regulation of several antioxidant defense enzymes and proteins, including catalase and thioredoxin, concomitant with the induction of apoptosis in WEHI7.2 mouse thymoma cells. To test whether this down-regulation plays a critical role in the mechanism of steroid-induced apoptosis, WEHI7.2 cells were transfected with rat catalase. Two clones, expressing 1.4-fold and 2.0-fold higher catalase specific activity, respectively, when compared with vectoronly transfectants were selected for further study. An increase to 1.4-fold parental cell catalase activity delayed cell loss after dexamethasone treatment, whereas a 2.0-fold parental catalase activity prevented dexamethasone-induced cell loss for 48 h after treatment. Dexamethasone treatment of the WEHI7.2 cells stimulated a release of cytochrome c into the cytosol. Catalase-overexpressing cells showed a delay or lack of cytochrome c release from the mitochondria, which correlated temporally with the delay or prevention of cell loss in the culture after dexamethasone treatment. A decreased amount of cell death from WEHI7.2 cells overexpressing catalase was also seen in tumor xenografts in severe combined immunodeficient mice when compared with tumors from vector-only transfected cells. Similarly, thioredoxin-overexpressing WEHI7.2 cells, shown previously to be apoptosis resistant, showed decreased cell death in tumor xenografts. This resulted in larger tumors from cells overexpressing these proteins. Cell death in control transfectant tumor xenografts was primarily attributable to apoptosis. In contrast, the cell death we observed in tumors from thioredoxin- or catalase-overexpressing cells had a higher frequency of a nonapoptotic, nonnecrotic type of cell death termed para-apoptosis. These data suggest that: (a) oxidative stress plays a critical role in steroid-induced apoptosis prior to the commitment of the cells to undergo apoptosis; and (b) resistance to oxidative stress can contribute to tumor growth.

The specific NOS2 inhibitor, 1400W, sensitizes HepG2 cells to genotoxic, oxidative, xenobiotic, and endoplasmic reticulum stresses.

We tested the hypothesis that the constitutive activity of the inducible form of nitric oxide synthase (NOS2) serves to protect cells against numerous endogenous stresses. To accomplish this, we treated HepG2 cell lines that were individually transfected with 13 different promoter/response element (RE) chloramphenicol acetyl transferase (CAT) reporter constructs, with a highly selective NOS2 inhibitor, 1400W [N-(3-(aminomethyl)benzyl) acetamidine)]. HepG2 cells were incubated for 6 h with 0, 1, 10, 50, 100, and 200 microM 1400W, and the activation of the promoter/RE CAT reporter constructs was simultaneously determined. The highest fold inductions occurred at 200 microM 1400W, a concentration that had no effect on overall cell viability, as determined by the MTT assay. Twelve of the 13 promoter/RE CAT reporter constructs were significantly activated by 200 microM 1400W. These results indicate the extensive protective role of constitutive NOS2 against genotoxic, oxidative, and endoplasmic reticulum stresses. The mechanism of this protection may involve the complexing of iron by nitric oxide (NO) to reduce hydroxyl radical formation, NO inhibition of electron transport and the generation of reactive oxygen species within mitochondria, NO inhibition of cyclooxygenase, lipoxygenase, and cytochrome P450 enzyme activity, and the scavenging of superoxide anions by NO to form peroxynitrite.

Ultrastructural evaluation of oocytes during atresia in rat ovarian follicles.

Mammalian females are born with a finite number of ovarian oocytes, the vast majority of which ultimately undergo degeneration by atresia. The overall process of ovarian follicular atresia has been morphologically well described only in large antral follicles. Additionally, little attention has been focused on ultrastructural changes in the oocyte. Furthermore, most such morphological studies were performed prior to identification of apoptosis as a mechanism of physiological cell death. Therefore, the purpose of this study was to use electron microscopy to compare the process of atretic oocyte degradation in ovarian follicles of female Fischer 344 rats (38 days old) with ultrastructural characteristics of apoptosis. Examination of ovarian follicles revealed that nucleolar segregation, cytoplasmic or nuclear condensation, apoptotic body formation, and chromatin margination along the nuclear membrane are never observed in atretic oocytes during the degenerative process. Instead, early morphological changes in atretic oocytes include retraction of granulosa cell- and oocyte-derived microvilli and condensation of mitochondria and loss of cristae. These occurrences coincide with initiation of granulosa cell apoptosis. After most granulosa cells are lost, more severe changes occur, including segmentation of the oocyte and cytoplasmic vacuolization as atresia progresses. Thus, these results suggest that, during atresia, oocytes are removed by physiological oocyte cell death, a method that does not involve classically described apoptosis.

Molecular models to analyse preprotachykinin-A expression and function.

Towards an understanding of the mechanisms controlling Preprotachykinin A (PPT) expression we have generated a variety of molecular models to determine the mechanisms regulating both the tissue-specific and stimulus-inducible expression of the PPT gene. The approaches used include transgenic and virus vector models complementing biochemical analysis of promoter interactions with transcription factors. We have identified and characterised a yeast artificial chromosome (YAC) containing the human PPT gene and generated transgenic mouse lines containing multiple copies of this chromosome on a normal mouse genetic background. This resulted in a pattern of expression in the nervous system remarkably similar to that reported for PPT mRNA in rodents. In addition, this transgenic model has been constructed in such a manner to allow for over expression of tachykinins based on the number of extra alleles in the transgenic mouse. These animals allow us to further examine the function of the tachykinins and acts as a useful complement to existing PPT ablated mice. In vitro we have introduced the proximal PPT promoter in reporter gene constructs into adult neurones in both DRG and the CNS by an adenoassociated virus (AAV) vector or by biolistic transfection respectively. Using the AAV vector we have demonstrated that the proximal promoter can mediate the effects of NGF in adult rat DRG. These models allow us to delineate transcriptional domains involved in the physiological and pathological expression of the PPT gene.